An anatomical review: the afferent and efferent pathways of the nucleus accumbens.

Objective: The nucleus accumbens is an important component of the ventral striatum. It is a round and flattened structure, which is located anterior to the posterior border of the anterior commissure and lies paralel to the midline. It has a crucial role in the cognitive processing of motivation, reward, addiction, aversion, slow-wave sleep and reinforcement learning. The aim of this study was to revisit the afferent and efferent pathways of the nucleus accumbens. Methods: A comprehensive literature review was performed using Pubmed and Google Scholar websites. Results: Neurons in the nucleus accumbens receive input from the ventral tegmental area (via the mesolimbic dopaminergic pathway), the amygdaloid complex (primarily via the ventral amygdalofugal pathway), from the hippocampal formation (through the precommissural fornix), and from cells of the bed nucleus of the stria terminalis. Additionally, fibers from the prefrontal cortex and prelimbic cortex project to the nucleus accumbens. Efferent projections of the nucleus accumbens include fibers to the hypothalamus, the ventral tegmental area, the substantia nigra, amygdala, the subpallidal region and the globus pallidus. The afferent and efferent pathways of the nucleus accumbens has been implicated in numerous neurological and psychiatric disorders, including depression, obsessive-compulsive disorder, bipolar disorder, drug addiction, Parkinson, Alzheimer and Huntington diseases. Conclusion: The nucleus accumbens is a complex and fascinating structure that has great influence over a variety of human behaviors. Knowing afferent and efferent pathways of the nucleus accumbens will guide to the physicians for diagnosis and treatment of the neurological and psychiatric disorders. [ABSTRACT FROM AUTHOR]